Abstract

Seeds of local black radish cultivar (experiment 1) were sown in plots, then plants were sprayed twice after thinning 2 weeks latter by Fe-EDDHA at rates of 0, 20, 30 or 40 mgL^-1. Whereas, seeds of nates carrot cultivar (experiment 2) were sown on plots and furrows, then plants were sprayed twice after thinning and once more at the commencement of root swollen after 3 months by indole-3-butyric acid (IBA) at rates of 0, 20, 30 or 40 mgL^-1. The objective of this investigations were to improve growth, yield and yield quality of radish and carrot irrigated whenever 25% of soil available water capacity (AWC) is depleted to a depth of 25 cm. Radish required 146.25 mm supplementary irrigation besides 254.3 mm rainfall incidences during the growing season. Radish yield was substantially increased, as plants sprayed by Fe-EDDHA especially, with 40 mgL^-1 rate which gave the highest yield (45.47 kgm^-2). Yield was linearly responded to iron rates, and yield responses to Fe-EDDHA rates could be estimated from the following equation: yield (kgm^-2) = [30.0178 + 0.3004 (iron rate)]. Carrots required 175.5 mm supplementary irrigation in addition to 254.3 mm rainfalls. Plot cultivation (11.8 kgm^-2) substantially exceeded its corresponding furrow cultivation (8.7 kgm^-2) in term of root marketable yield. Yield was quadratically responded to varying IBA rates and could be estimated by the following equation: yield (kgm^-2) = [10.0482 – 0.0558358 (IBA rate) + 0.0019168 (IBA rate)^**2]. The highest marketable yield (12.6 kgm^-2) was obtained from plot cultivated plants sprayed by IBA rate of 40 mgL^-1.

Key words: Radish, carrot, IBA, Fe-EDDHA, supplemental watering.